This invention relates to a hub for receiving and securing a reel of recording tape, particularly a relatively large reel of the type used for commercial recording and replay purposes.
Prior art devices generally include a two-piece hub having a base portion and a removable top portion. To secure the reel to the hub, the top portion thereof must first be removed to enable the reel to be placed into cooperation with the base portion. The top portion of the hub is then positioned over the tape reel and clamped into engagement with the base portion to maintain the reel securely in place. Thereafter, in order to remove the reel, the top portion must be disengaged from the base portion and removed. Other prior art hubs utilize manually-set indexing means to mechanically retain the reel in place.
Though such prior art hubs have operated well in maintaining tape reels in place, the successive removal and re-engagement of the top portion of the hub or the manual setting of indexing means each time a reel is added or removed has sometimes proved to be a time-consuming and cumbersome task. This has been particularly true when an operator must hold large, flangeless reels with one hand while manipulating the top portion or the indexing portion of the hub with the other. Under such circumstances, tape may undesirably unravel from the reel, wasting time and sometimes ruining the tape.
The invention overcomes these and other deficiencies in the prior art by providing a unitary hub having detent means for releasably maintaining a reel of recording tape in position with minimal operator participation. More particularly, the hub of the invention includes a housing having a plurality of openings, preferably three, through which a corresponding plurality of resilient detents, such as spring-loaded balls are adapted to retractably protrude. The interior of the housing has guide means which provide a path for the spring-loaded balls upon retraction thereof.
When a reel of recording tape is positioned over the balls toward the base of the hub, the balls are urged against the force of the associated springs, causing the balls to retract through the corresponding openings in the housing and along the path provided by the guide means. After the reel has passed over the balls, the force of the springs urges them to protrude through the openings in the housing where they apply pinching forces to the reel for maintaining the reel securely in place. Thereafter, the reel can be removed simply by pulling it back over the balls and off of the hub.
Since the balls are of relatively large diameter, they offer relatively little friction with the reel, thereby minimizing the force required to position and remove the reel. Moreover, the tape hub is electrically grounded in order to dissipate any spurious charges that may develop, particularly those produced by static electricity. Finally, the hub is provided with a fluted top, adapted to permit controlled manual rotation of the reel, whereby the hub can be used as an editing knob for altering or rearranging the tape, and easily handled when positioned on or off of a turntable spindle.